void Tree::generate(uint8_t limit)
{
uint8_t darkness=1;
srand((uint32_t)time(NULL));
uint8_t m_trunkHeight = getRandInt(MIN_TRUNK,limit);
bool smalltree=false;
//in this implementation we generate the trunk and as we do we call branching and canopy
if(m_trunkHeight<BRANCHING_HEIGHT)
{
smalltree=true;
darkness=0;
}
uint8_t th=m_trunkHeight-1;
uint8_t i;
for(i = 0; i < th; i++)
{
if(smalltree)
{
Trunk* v = new Trunk(_x,_y+i,_z,darkness);
if(i>=MIN_TRUNK-1){
m_Branch[n_branches]= v;
n_branches++;
}
else
{
delete v;
}
}
else
{
Trunk* v = new Trunk(_x,_y+i,_z,darkness);
if(i>BRANCHING_HEIGHT-1)
{
generateBranches(v);
}
else
{
delete v;
}
}
}
Trunk* v = new Trunk(_x,_y+i,_z,darkness);
m_Branch[n_branches]= v;
n_branches++;
generateBranches(v);
generateCanopy();
}
void Tree::generate(uint8_t limit)
{
const uint8_t m_trunkHeight = uniformUINT8(MIN_TRUNK, limit);
bool smalltree = false;
uint8_t type = 0;
if (m_trunkHeight < BRANCHING_HEIGHT)
{
smalltree = true;
}
if (uniform01() > 0.5) // 1/2 chance
{
++type;
if (uniform01() > 0.5) // 1/4
{
++type;
}
}
for (unsigned int i = 0; i + 1 < m_trunkHeight /* Trunk Height */; ++i)
{
if (smalltree)
{
const TrunkPtr v(new Trunk(_x, _y + i, _z, _map, type));
if (i >= MIN_TRUNK - 1)
{
m_Branch[n_branches++] = v;
}
}
else
{
const TrunkPtr v(new Trunk(_x, _y + i, _z, _map, type));
if (i > BRANCHING_HEIGHT - 1)
{
generateBranches(v);
m_Branch[n_branches++] = v;
}
}
}
const TrunkPtr v(new Trunk(_x, _y + m_trunkHeight - 1, _z, _map, type));
generateBranches(v);
generateCanopy();
m_Branch[n_branches++] = v;
}
void Tree::generateBranches(TrunkPtr wrap)
{
int32_t x = wrap->_x;
uint8_t y = wrap->_y;
int32_t z = wrap->_z;
uint32_t schanse = BRANCHING_CHANCE;
if (uniform01() > 1.0 - (1.0 / BRANCHING_CHANCE))
{
const double r = uniform01();
if (r < 0.2)
{
x--;
}
else if (r < 0.4)
{
x++;
}
else if (r < 0.6)
{
z++;
}
else if (r < 0.8)
{
z--;
}
if (r > 0.5)
{
y++;
}
const TrunkPtr v(new Trunk(x, y, z, _map));
m_Branch[n_branches++] = v;
generateBranches(v);
}
}
std::size_t BppSolver::branchAndPrice(BinPackingProblem& bpp)
{
TreeNodes nodes;
nodes.emplace_back();
nbGeneratedNodes = 0;
while (!nodes.empty())
{
BranchNode& node = nodes.back();
if (node.toPrune)
{
for (auto i : *node.invalidColumns)
BPmodel.setVarUB(i, 1.0);
if (node.id >= 0)
//pricerBranchConstraints[node.id].end();
pricerModel.removeConstraint(node.id);
#ifdef EXPORT_MODEL
BPSolver.exportModel("model.lp");
pricerSolver.exportModel("pricer.lp");
#endif // !EXPORT_MODEL
nodes.pop_back(); // delete the node.
}
else if (std::ceil(node.incumbentLPValue) <= upperBound)
{
// modify the master and pricer to solve the specific node
// desable ~current and incumbent invalide variables
for (auto i : *node.invalidColumns)
BPmodel.disableVar(i);
// add the specific pricer branch constraint
IloExpr expr(pricerModel.getEnv());
if (node.brType == TOGETHER)
{
expr += pricerModel.getVar(node.couple_ij.first) - pricerModel.getVar(node.couple_ij.second);
pricerModel.addConstraint(expr, 0.0);
}
else if (node.brType == SEPARATE)
{
expr += pricerModel.getVar(node.couple_ij.first) + pricerModel.getVar(node.couple_ij.second);
pricerModel.addConstraint(expr, 1.0);
}
expr.end();
#ifdef EXPORT_MODEL
BPSolver.exportModel("model.lp");
pricerSolver.exportModel("pricer.lp");
#endif // !EXPORT_MODEL
// generate columns
real master_lp_value = columnGeneration(bpp);
//std::cout << master_lp_value << "\n";
// is solution integral
if (BPmodel.checkIntegrality())
{
std::cout << "---------------- INTEGRAL -----------------\n";
// possible new upper bound
if (std::ceil(master_lp_value - EPS) < upperBound)
{
// update upper bound
upperBound = master_lp_value;
// copy the current solution
bestSolution = BPmodel.getPrimalValues();
}
node.toPrune = true;
//else if (master_lp_value == upperBound) // optimal
// return upperBound;
}
else if (std::ceil(master_lp_value) < upperBound) // generate branchs
{
auto couple = ryanFosterCouple(node);
node.toPrune = true;
generateBranches(master_lp_value, couple, node, nodes);
}
else
{
// no node to generate, then this node must be pruned
node.toPrune = true;
}
}
else
// to prune
node.toPrune = true;
} while (!nodes.empty());
return (std::size_t)upperBound;
}
